Laser beam irradiation device

ABSTRACT

A laser beam irradiation device according to the present invention is equipped with very strict safety means, thereby assuring that a user can use it safely.  
     A hand-held applicator has a face H formed on its top, and a push button switch S 4  on its side. The face H has a spherical lens  31  press-fitted in its center hole, and the face H has a hollow cylinder  32  integrally connected to its circumference, encircling the spherical lens  31 . The hand-held applicator is applied to one&#39;s skin by the hollow cylinder  32  at its edge.  
     The hollow cylinder  32  has a cylindrical electrode  33  embedded in and somewhat projecting forward. A heat sink  34  is placed behind the spherical lens  31 , and a semiconductor laser diode  35  is press-fitted in the through hole, which is made in the center of the heat sink  34 .  
     A cooling fan  36  is placed behind the heat sink  34.

TECHNICAL FIELD

[0001] The present invention relates to a laser beam irradiation devicefor projecting a laser beam to one's skin for beauty treatments such asskin treatment, removal of undesired hair and suchlike to make personsmore beautiful.

BACKGROUND ART

[0002] A laser beam is a very strong beam of controlled light whoseenergy density is much larger than that of a light beam from an ordinarylight source, and therefore, exposure of a living body to the laser beamraises the temperature of an exposed spot high enough to injure ordamage the spot by heat or transform its protein.

[0003] Especially, eyes, which are the light sensitive organs, can beincurably damaged, and so it is very dangerous to radiate the laser beamdirectly onto one's eye. The laser beam is a very strong beam ofdirection-controlled light so that the light power remains as high inthe distance as it is at the light source or laser, and therefore,radiation of the laser beam onto an eye even from a remote light sourceis still hazardous to the eye.

[0004] Therefore, it is of a great concern that a beauty treatment laserdevice that is to be handled by a general user for skin treatment orremoval of undesired hair be equipped with very strict safety means forpreventing inadvertent projection of the laser beam to light-sensitiveorgans, such as eyes.

[0005] In view of this, one object of the present invention is toprovide a laser beam irradiation device whose control circuit isequipped with foolproof safety means, thereby assuring that a generaluser can use the device with absolute safety.

SUMMARY OF THE INVENTION

[0006] To attain this object a laser beam irradiation device accordingto the present invention, specifically as defined in claim 2 comprises:

[0007] a hand-held applicator;

[0008] a semiconductor laser diode for radiating a laser beam;

[0009] a radiation switch for turning the laser diode on and off;

[0010] a touch sensor attached to the top of the hand-held applicator;

[0011] a standby switch for putting the device on standby condition forradiation;

[0012] an automatic switching means responsive to expiration of apredetermined time subsequent to the turning-on of the standby switchfor automatically turning the standby switch off; and

[0013] a safety circuit responsive both to the touching of at least oneportion of the touch sensor to the body and to the turning-on of thestandby switch, and subsequent turning-on of the radiation switch forpermitting a working current to flow in the semiconductor laser diodefor radiating the laser beam.

[0014] The laser beam irradiation device according to claim 3 is adevice as defined in claim 2, using an electrically conductive cylinderas the touch sensor, the cylinder projecting forward from the front partof the top of the hand-held applicator.

[0015] The laser beam irradiation device according to claim 4 is adevice as defined in claim 2, using two electrically conductive rods asthe touch sensor, the rods projecting forward from the front part of thetop of the hand-held applicator.

BRIEF DESCRIPTION OF DRAWINGS

[0016]FIG. 1 is a perspective view of a laser beam irradiation deviceaccording to the present invention;

[0017]FIG. 2 is a front view of one example of the hand-held applicator

[0018]FIG. 3 is a side view of the hand-held applicator, partly insection;

[0019]FIG. 4 is a block diagram of the control circuit;

[0020]FIG. 5 is a front view of another example of hand-held applicator;and

[0021]FIG. 6 is a side view of the hand-held applicator of FIG. 5,partly in section.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0022] The present invention is described below in respect of preferredembodiments.

[0023]FIG. 1 shows how it looks in appearance.

[0024] The laser beam irradiation device comprises a major body 10 andan associated hand-held applicator 30 connected to the major body via agiven length of cable 20.

[0025] The major body 10 contains a control circuit 40, and the housingof the major body 10 has a recessed compartment 50 for accommodating thehand-held applicator 30 and a console 60 on its top surface, and a lid70 hinged to one side of the housing.

[0026] A power switch S1, a standby switch S2 and a radiation timesetting switch S3 are arranged on the console 60.

[0027] Also, an LED power-on indicator lamp L1, a standby indicator lampL2 and a six-step radiation time indicator lamp L3 are arranged next tothe power switch S1, the standby switch S2 and the radiation timesetting switch S3 on the console 60 respectively.

[0028] The six-level radiation time indicator lamp L3 comprises red andgreen LED chips in a single transparent enclosure. These LED chips areselectively or all together turned on to produce three different coloredlights, namely, red, green and yellow or amber.

[0029] The power switch S1 when operated makes the power supply in themajor body 10 turn on and off.

[0030] Accordingly the power-on indicator lamp L1 turns on and off.

[0031] When the standby switch S2 is turned on, the laser is set on astandby condition for radiation and the standby indicator lamp L2 turnson. When the standby switch S2 is turned off, the standby condition ofthe laser is cancelled and the standby indicator lamp L2 turns off.

[0032] The mere switching-on of the power switch S1 keeps the laser stayin non-standby condition.

[0033] When the standby switch S2 turns on, an associated timer startscounting to automatically turn off the standby switch S2 after apredetermined period (fro example, 20 minutes) has passed irrespectiveof whether or not the laser has been radiated.

[0034] The radiation time setting switch S3 is responsive to each pushfor selectively setting a radiation dose of each shot in an intermittentradiation among the levels one to six.

[0035] The six-level radiation time indicator lamp L3 changes its lightsequentially in the order of green, blinking green, amber, blinkingamber, red and blinking red in response to the sequential change of theradiation dose from the levels one to six.

[0036] The radiation time setting switch S3 can be operated to set adesired radiation period even if the standby switch S2 is on.

[0037] The initial radiation dose is automatically set at the level onein response to the turning-on of the power switch S1.

[0038] The shot-to-shot interval in the intermittent radiation isdetermined (for example, 1.5 seconds) beforehand.

[0039] Referring to FIGS. 2 and 3, the hand-held applicator 30 has aface H projecting laterally from its top, and a push button switch S4 onits side.

[0040] Also, the hand-held applicator has vent holes “a” and “b” at thelower part and on the rear side of the face H.

[0041] The face H has a spherical lens 31 press-fitted in its centerhole, and the face H has a hollow cylinder 32 integrally connected toits circumference, encircling the spherical lens 31. The hand-heldapplicator 30 is applied to one's skin by the hollow cylinder 32 at itsedge.

[0042] A coaxial cylindrical electrode 33 is embedded in the hollowcylinder 32 to project forward therefrom at its open edge.

[0043] A heat sink 34 is placed behind the spherical lens 31, and asemiconductor laser diode 35 is press-fitted in a through-hole bored inthe center of the heat sink 34.

[0044] A cooling fan 36 is placed behind the heat sink 34.

[0045] The laser beam from the semiconductor laser diode 35 focuses onthe focal point of the spherical lens 31 in the focal plane, in whichthe opening of the hollow cylinder 32 lies. The focal length of thespherical lens 31 is short enough to converge all the light energy to alimited spot, allowing the so converged beam to diverge beyond the focalpoint with the result that the light energy is distributed over theextensive area.

[0046] Accordingly the light energy density drastically decreases withthe distance from the focal point, and therefore, there is little or nofear of injuring a living body even if it is exposed to the so dispersedlight beam.

[0047] The heat sink 34 allows the heat generated by the semiconductorlaser diode 35 to transmit therethrough. Thus, the semiconductor laserdiode 35 is prevented from lowering its output.

[0048] The heat sink 34 is made of aluminum or aluminum alloy, whosethermal conduction is relatively high, and the heat sink 34 has furtherthrough holes made therein to effectively improve its heat radiation.

[0049] The semiconductor laser diode 35 may be a PN junction diode ofGaAs or any other compound semiconductor, which can be excited by makingan electric current flow therethrough for laser oscillation.

[0050] The peak-to-peak wavelength of the semiconductor laser diode is600 to 1600 nm long, and the laser output ranges from 5 mW to 3W,thereby efficiently causing a sufficient photothermal reaction on theskin.

[0051] Further caused are additional optical effects other than therequired photothermal reaction, such as photoelectric effect,photo-magneto effect, photo-dynamics effect, photochemical effect,photo-immunizing effect, photo-zymogenesis effect and the like. Thephoto-biological activation expedites the body's metabolism and bloodcirculation under the skin. The laser beam is hardly absorbed by thewater contents and blood, and therefore, it can reach deep under theskin.

[0052]FIG. 4 shows the control circuit of the laser beam irradiationdevice.

[0053] It comprises: a CPU 41 having a memory 42 and a timer circuit 43both built therein; a standby switch S2, a radiation time setting switchS3, a push button switch S4 and a touch sensor circuit 45 for detectingthe touching of the electrode 33 on the skin, of which all the switchesand touch sensor circuit being connected on the input side of an I/Oport 44; and a drive circuit 46 connected on the output side of the I/Oport 44 for controlling the working current in the semiconductor laserdiode 35.

[0054] The touch sensor circuit 45 comprises a high-frequency oscillatorcircuit and a switching circuit responsive to the working or non-workingof the oscillator for turning on or off.

[0055] The electrode 33 is connected to one terminal of an oscillationcoil of the oscillator circuit, and the oscillation stops as theelectrode 33 touches the skin. The switching circuit is responsive tothe stop of the oscillation for turning off.

[0056] The touch sensor circuit 45 may include an impedance element suchas a capacitance or a resistance whose impedance drastically varies inresponse to the touching of the electrode to the skin, or may include aswitching element or a piezoelectric element responsive to the touchingof the electrode to the skin.

[0057] The CPU 41 carries out the on-and-off control of the workingcurrent from the drive circuit 46 under the control of the timer circuit43.

[0058] The timer control includes two different modes, that is, thetreatment time control in which the working current is made to flow apredetermined length of time for each treatment, and the radiation dosecontrol in which the working current is made to flow a predeterminelength of time for each shot in the intermittent radiation.

[0059] The length of time for a single dose can be set by the radiationtime setting switch S3.

[0060] In carrying out a required beauty treatment with the soconstructed laser beam irradiation device of the present invention,first the power switch S1 is turned on.

[0061] Then, the radiation setting switch S3 is kept being pushed untilan indication representing a required length of time for radiationappears. When the indication appears, the switch S3 is released, thussetting the time for a single dose.

[0062] Next, the standby switch S2 is turned on to put the device in thestandby condition.

[0063] The hand-held applicator 30 is held in hand with the face Hdirected towards a selected spot on the skin at the angle of 90 degreesrelative to the skin, and then, the electrode 33 of the cylinder 32 ispushed against the selected spot.

[0064] Then, the push button switch S4 is depressed to turn on thesemiconductor laser diode 35 for predetermined seconds, and then turnsoff for prescribed seconds.

[0065] The semiconductor laser diode 35 turns on or off alternately,thus, the skin is exposed to the intermittent radiation of laser beam.

[0066] A required beauty treatment is repeated as many times as requiredwhile moving the electrode 33 of the hand-held applicator 30 from placeto place on the skin.

[0067] The radiation of the laser beam is made to stop in response tothe electrode 33 being taken off from the skin, and the radiation of thelaser beam is made to start in response to the electrode 33 being put onthe skin.

[0068] Assuming that a fixed length of time has passed since theturning-on of the standby switch S2, it automatically turns off, therebystopping the radiation of the laser beam.

[0069]FIGS. 5 and 6 are front and side views of the hand-held applicator30 having two rod-like electrodes 33 on its face front.

[0070] As shown in the drawings, two rod-like electrodes 33 standupright on the face front ahead of the spherical lens 31, which isplaced in the center of the face H.

[0071] The rod-like electrodes 33 are of electrically conductive metal,and their ends may be rounded or flattened. They may be gold-plated.

[0072] Three or more rod-like electrodes may be used. Depression of thepush button switch S4 causes radiation of the laser beam, provided thatany one or more of the rods 33 be put in contact with the skin.

INDUSTRIAL APPLICABILITY

[0073] As described above, the laser beam irradiation device of thepresent invention is responsive to the touching of at least a part ofthe touch sensor onto the skin for making a working current flow in thesemiconductor laser diode for radiation, provided that the standbyswitch is on, and that the radiation switch turns on

[0074] Therefore, erroneous depression of the radiation switch prior tothe touching of the face of the hand-held applicator onto the skin doesnot permit radiation of the laser beam, assuring that the laser beamirradiation device be used safely.

[0075] Removal of the hand-held applicator apart from the skin makes thelaser beam automatically stops, thereby preventing any danger ofmiss-radiation that may be caused by inadvertent removal of thehand-held applicator from the skin.

[0076] The laser beam cannot be radiated without turning the standbyswitch on, thus assuring that radiation of the laser beam cannot becaused except for the beauty treatment being carried out.

[0077] On the expiration of a predetermined time subsequent to theturning-on of the standby switch the automatic switching means makes thestandby switch turn off, thus preventing the laser beam from radiatingany longer.

[0078] The touch sensor as in the present invention is given in the formof an electrically conductive cylinder or two or more electricallyconductive rods, somewhat projecting ahead of the face front.

[0079] This arrangement makes it unnecessary to keep the face front ofthe hand-held applicator pushed flat against the skin surface during thebeauty treatment, thereby facilitating application of the hand-heldapplicator onto the skin. Accordingly the hand-held applicator can behandled smoothly.

1. (Deleted)
 2. A laser beam irradiation device comprising: a hand-heldapplicator; a semiconductor laser diode for radiating a laser beam; aradiation switch for turning the laser diode on and off; a touch sensorattached to the top of the hand-held applicator; a standby switch forputting the device on standby condition for radiation; an automaticswitching means responsive to expiration of a predetermined timesubsequent to the turning-on of the standby switch for automaticallyturning the standby switch off; and a safety circuit responsive both tothe touching of at least one portion of the touch sensor to the body andto the turning-on of the standby switch, and subsequent turning-on ofthe radiation switch for permitting a working current to flow in thesemiconductor laser diode for radiating the laser beam;
 3. A laser beamirradiation device according to claim 2 wherein it uses an electricallyconductive cylinder as the touch sensor, the cylinder projecting forwardfrom the front part of the top of the hand-held applicator.
 4. A laserbeam irradiation device according to claim 2 wherein it uses twoelectrically conductive rods as the touch sensor, the rods projectingforward from the front part of the top of the hand held applicator.